Glass, and in particular chemically strengthened glass, has become the material of choice for viewscreens of many, if not most, consumer electronic products. For example, chemically strengthened glass is particularly favored for “touch” screen products, including small items, such as cell phones, music players, e-book readers and electronic notepads, or larger items, such as computers, automatic teller machines, airport self-check-in machines and other similar electronic items. Many of these items may require the application of antireflective (“AR”) coatings on the glass in order to reduce the reflection of visible light from the glass and thereby improve contrast and readability, particularly when the device is used in direct sunlight. However, drawbacks of the AR coating can include its sensitivity to surface contamination and poor anti-scratch reliability. Fingerprints and stains on an AR coating are very noticeable on an AR coated surface. As a result, it may be desirable that the glass surface of a touch device be easy to clean which may be achieved by applying an easy-to-clean (“ETC”) coating to the glass surface.
The current processes for making glass articles having both antireflection and easy-to-clean coatings require that the coatings be applied using different equipment and, consequently, separate manufacturing runs. The basic procedure is to provide a glass article; apply the antireflection (“AR”) coating using, for example, a chemical vapor (“CVD”) or physical vapor deposition (“PVD”) method. The optical coated (such as AR coated) articles may be transferred from the coating apparatus to another apparatus to apply the ETC coating on top of the AR coating. While these processes can produce articles that have both an AR ETC coating, they require separate runs and have higher yield losses due to the extra handling that is required. They may also result in poor reliability of the final product because of contamination arising from the extra handling between the AR coating and ETC coating procedures. Further, in a state-of-the-art 2-step coating process, applying an ETC coating over an optical coating can result in a coating that is easily scratched in touch applications where the user uses a finger to access and use an application on a device, and then uses a cloth to wipe off finger oils and moisture that create haze on the touch surface. While the AR coated surface can be cleaned before applying the ETC coating, this involves additional steps in the manufacturing process. These additional steps increase product costs. Consequently, it is highly desirable to find a process in which both coatings can be applied using the same basic procedure and equipment, thus reducing manufacturing costs.